Nerve growth factor enhances nerve regeneration through fibronectin grafts

Soluble fibronectin and nerve growth factor (NGF) promote axonal regeneration when placed in silicone tubes. We investigated the ability of orientated fibronectin mats to bind and release bioactive NGF and the possibility of augmenting axonal regeneration following axotomy by using fibronectin conduits impregnated with NGF. The release of NGF was quantified using a fluorometric ELISA and bioactivity confirmed with a neuronal culture bioassay. Immunohistochemical techniques and computerized image analysis were used to assess the rate and volume of axonal and Schwann cell regeneration. The delivery of NGF to the site of injury produced an increase in the rate (P < or = 0.007) and volume (P < or = 0.004) of both axonal and Schwann cell regeneration when compared to conduits of plain fibronectin. We conclude that the local delivery of NGF by impregnated fibronectin conduits enhances axonal regeneration.